Thio-urea compound and process of making same.



UnirTnn STATES PATENT OFFICE.

ADOLF ISRAEL AND RICHARD KOTI-IE, OF ELBERFELD, GERMANY, ASSIGN- ORS TO THE FARBENFABRIKEN OF ELBERFELD 00., OF NElV YORK, N. Y.

THIU UFHEA COMPOUND AND PROCESS OF MAKING SAME.

SPEGZFICATION forming part of letters Patent No. 675,628, dated June 4, 1901.

Application filed December 27,1900. Serial No. 41,246. (No specimens.)

To all zuhont it may concern:

Be it known that we, ADoLn ISRAEL and RICHARD KOTHE, doctors of philosophy,chemists, (assignors to the FARBENFABRIKEN on ELBEEFELD COMPANY, of New York,) residing at Elberfeld, Germany, have invented a new and useful Improvement in Thio-Urea Compounds and Processes of Making Same; and we hereby declare the following to be a clear and exact description of our invention.

Our invention relates to the production of a new thio-urea compound derived from amidonaphthol sulfonic acids, being an alkaline salt of an acid having the following formula:

l l l l l l l so n. Oh The process of producing this body consists in heating an equimolecular mixture of beta amido alpha naphthol beta ,1 sulfonic acid and beta -amido alpha naphthol beta -sulfonic acid with carbon bisulfid (CS and sulfur in a neutral or slightly-alkaline solution. A condensation of the two above-named amidonaphthol sulfonic acids with one molecule of carbon bisulfid takes place under evolution of one molecule of sulfureted hydrogen,the above-defined thio-urea derivative being thus formed according to the following equation:

l l l 'll +sin.

The new thio-urea derivative thus obtained may be employed for the manufacture of valuable azo dyestuffs.

In carrying out our new process practically we can proceed as follows, (the parts being by weight:) To a solution of twelve parts of beta amido alpha naphthol-beta sulfonic acid and of twelve parts of beta -amidoalpha -naphthol-beta -sulfonic acid in about from two hundred to three hundred parts of water, to which so much sodium carbonate has been added as to render it slightly alkaline, we add two hundred to three hundred parts of ethylic alcohohfrom twenty to twentyfive parts of carbon bisulfid, and from 0.4 to 0.5 parts of powdered sulfur. The mixture thus obtained is boiled in a vessel provided with a reflux-condenser until the evolution of sulfureted hydrogen ceases. After the alcohol and the superfluous carbon bisulfid have been distilled off the reaction mixture is filtered in order to remove the sulfur which has been precipitated. The filtrate is then acid ulated by means of hydrochloric acid and the thio-urea derivative is precipitated from the acid solution by the addition of common salt. Forfurther purification it is extracted with water, filtered, and then precipitated again by the addition of common salt. The

pure sodium salt of the new body thus obtained crystallizes from water containing common salt in the shape of white crystals, which are readily soluble in cold and very readily in hot water and soluble with difficulty in alcohol. The barium salt represents white flakes, which are soluble in cold and readily soluble in hot water. The calcium salt is readily soluble in water. These salts are prepared by the addition of solutions of barium chlorid (BaOl or of calcium chlorid (OaCl to watery solutions of the sodium salt of the said thio-urea derivative. On boiling the thio-urea derivative with the twentyfold quantity of hydrochloric acid of twenty per cent. it dissolves, and after boiling for some time beta -amido-alpha -naphthol-beta -sulfonic acid and beta -amido-alpha -naphthol-beta -sulfonic acid are regenerated.

The new thio-urea derivative is capable of combining with one and likewise with two molecules of diazo compounds, thus furnishing valuable azo dyestuffs.

Having now described our invention and in what manner the same is to be performed, what we claim as new, and desire to secure by Letters Patent, is-

1. The process for prod ucing a new thio-urea derivative of amidonaphthol sulfonic acids by, first, dissolving an equimolecular mixture of beta -amido-alpha -naphthol-beta -sulfonic acid and beta -amido-alpha -naphthol-beta sulfonic acidin water with the addition of sodium carbonate; secondly, heating this solution after the addition of carbon bisulfid, sulfur and alcohol, and, finally, isolating the resulting thio-urea derivative, substantially as hereinbefore described.

2. The herein-described new thio-urea derivative which in the form of the free acid has the following formula:

ADOLF ISRAEL. RICHARD KOTHE.

Witnesses:

OTTO KONIG, J. A. RITTERSHAUS. 

